Well, uh.
I decided to put this idea into practice since I've seen Asgore's Journal in Undertale.
I often wondered if there was more to the King's entries than "Nice day today!"

So...that's how this story was born.

I hope, nonetheless, that you'll enjoy it!

ENTRIES 1 & 2: GRIEF AND RISING THOUGHTS

Frisk was drinking a glass of lemonade, while looking at the diary they picked up from Asgore's room. Now, they weren't the type of child to pry into anyone's secrets, but the bizzare fact that every single entry was filled with only three words, made them wonder if there wasn't more to those entries than they thought at first.

They accidentally dropped a little lemonade over one of the pages that they were looking at, and next to the three words, they noticed there was something else written.

"...no longer like this."

Maybe I shouldn't do this..., Frisk was thinking as they looked at the four revealed words before their eyes. Dad trusts me completely, and i-if he finds out I read through his diary...he'll probably be mad.

Come on, give it a try...Chara hissed in the back of their mind, I'd be curious if I were you.

Shut up, Chara. This isn't right... Frisk chided Chara for their lack of thought, ...I learnt that doing something like this is most likely illegal.

Frisk, even if he finds out..., Chara huffed, he'll realise that he wasn't honest with you. So...he won't be exactly mad.

Still, I can't do this, not after he... Frisk hesitated for a moment, before Chara took control and spilled the rest of the lemonade on the page. The child's eyes widened in shock as they read the full entry revealed before them — an entry filled with grief and...

Abandon.

Entry number 1, year 19xx

Nice day today!...No longer like this.

I remember the day when Toriel discovered the secret basement in which I kept the SOUL containers. Light was slowly pulsing from them, as if vaguely recognizing her, while her eyes were filled with tears and held her paw close to her chest.

She was angry.

I could see it in her expression as she turned towards me, eyes threatening to spill the tears that I saw — and threatening to burn me to a crisp — yet she didn't run away, for now.

I can still her trembling voice as she carressed the two SOULS we captured, whispering their names. Those were Patience and Bravery, both captured a day after another — they must've been siblings, by the way the boy with the orange SOUL was acting.

Their strength, their determination...

The girl attempted to kill a few of us, but fortunately, she was stopped in time by one of our loyal subjects.

How many of these other kids have attempted Genocide...? Chara wondered.

"Did they really have to attempt it...?" Frisk thought, terror rising in their SOUL as they kept on reading.

But her brother was actually disappointed with Patience's choices.

And when he was killed, he only uttered these words, "Don't let Toriel be harmed..."

I hope the next children won't be as perilous as these two...

Look at the dates...They were way before you fell down, Chara, Frisk noted. But why doesn't he mention Asriel?

Maybe he is in the later entries... Chara mused, I still feel...

Empty? Hollow? Soulless? Gone? Frisk enumerated a few adjectives out of their mind. Look, we did True Pacifist, together! And you always asked me about Asriel, if and how could we save him. But he explicitly said, there's no way for him to be saved...

Well, not right now, unfortunately.

"Frisk, dinner's ready! Please, come down, my child!" Toriel's voice made them snap to reality, as they closed the diary and rushed out of Asgore's bedroom — inadvertently bumping into the large goat monster, who was their Dad.

"What's got you in such a hurry, pumpkin?" Asgore asked in his usual, soft baritone voice. "I know Tori's food is absolutely delicious, but you still have to wash your hands."

"Yeah, Daddy, I know!" Frisk laughed. "Though my conscience wants me to tell you I've been reading your di— "

Nu-uh, not yet, Frisk. You need to tell him, but not right now.

CHARA! You know that I'm determined to—

"Frisk? Uh...child?" Asgore waved one of his large paws in front of Frisk's eyes.

"S-Sorry, Dad." Frisk excused themselves. "I'll be down in a minute."

But for Frisk and Chara, the emotional rollercoaster was just about to begin. They didn't know that the king was hiding a lot of pain and sorrow underneath that happy-go-lucky attitude of his — well, he and Toriel were back forming a couple, but only thanks to Frisk's hinted suggestions — and they were pretty sure their mother reluctantly accepted just because they believed in Asgore after all this time.

Later that evening, Toriel and Asgore went out for a stroll in the park, under the beautiful moonlight, giving Frisk the opportunity to read the second entry of the King's diary.

Entry number 2, year 19xx

Nice day today!...

At least this one did go without any human falling down.
Toriel seems to have grown distant with me — she's not even replying to my morning greetings — yet I find her looking at me with sorrow and longing, sometimes.

I understand what she must be going through.

But we have to keep on breaking this barrier somehow.

We've been trapped in here for centuries, and...

I don't know if I can handle this anymore.